[+cc Mario, Shyam, Brijesh] On Sat, Jan 28, 2023 at 10:39:51AM +0900, Damien Le Moal wrote: > PCI passthrough to VMs does not work with AMD FCH AHCI adapters: the > guest OS fails to correctly probe devices attached to the controller due > to FIS communication failures. What does a FIS communication failure look like? Can we include a line or two of dmesg output here to help users find this fix? AMD folks: Can you confirm/deny that this is a hardware erratum in this device? Do you know of any other devices that need a similar workaround? > Forcing the "bus" reset method before > unbinding & binding the adapter to the vfio-pci driver solves this > issue. I.e.: > > echo "bus" > /sys/bus/pci/devices/<ID>/reset_method > > gives a working guest OS, thus indicating that the default flr reset > method is defective, resulting in the adapter not being reset correctly. > > This patch applies the no_flr quirk to AMD FCH AHCI devices to > permanently solve this issue. > > Reported-by: Niklas Cassel <niklas.cassel@xxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> > --- > drivers/pci/quirks.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 285acc4aaccc..20ac67d59034 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -5340,6 +5340,7 @@ static void quirk_no_flr(struct pci_dev *dev) > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x1487, quirk_no_flr); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x148c, quirk_no_flr); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x149c, quirk_no_flr); > +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AMD, 0x7901, quirk_no_flr); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_no_flr); > DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_no_flr); > > -- > 2.39.1 >
